1. Field of the Invention
The present invention relates to the domain of mobile (or cellular) communication networks, and more precisely to mobile communication networks of the UMA (Unlicensed Mobile Access) type, defined by the technical specifications of the 3GPP TS 43.318 v6.4.0, “Generic access to the A/Gb interface-stage 2” (release 6), and TS 44.318 v6.3.0-“Generic Access (GA) to the A/Gb interface, Mobile GA interface layer 3 specification” (Release 6).
2. Description of the Art
As it is known by the man skilled in the art, an UMA network must comprises UMA access node called UNC (UMA Network Controller) to interface with mobile switching center(s) (MSC) belonging to its circuit switched (CS) core network and to serving GPRS support node(s) (SGSN) belonging to its packet switched (PS) core network.
In order a mobile station could exchange data with the UMA network, a permanent TCP (Transmission Control Protocol) connection must be established with an UNC, through which the CS and PS protocols are supported, after an authorization phase. Since a TCP connection is natively a transport connection oriented protocol, an UNC is a standalone machine supporting altogether CS and PS services, according to the 3GPP UMA standard.
From a network topology perspective, an UNC is comparable to a GERAN BSC (GSM EDGE Radio Access Network Base Station Controller) as it offers access to a core network by means of A and Gb interfaces respectively for CS and PS core network parts.
A BSC of a GERAN necessitates solid CPU capacities to handle radio resource management algorithms and plays a role of concentration node in a TDM transmission network organized with base stations (BTSs) in a star configuration. Therefore altogether for CPU reasons and transmission network organization, the BSCs are very justified as dedicated access network nodes.
An UMA access network having a number of specificities compared to a GERAN network, an UNC i) must have much less CPU requirements as it does not handle radio resource management algorithms with complex radio optimization features, ii) is merely a protocol gateway function for the CS core network part and a forwarding machine for the PS core network part, and iii) supports WiFi access point through a native IP network and therefore is not subject to any topology constraints linked to TDM transmission network.
So, even though an UNC stands as a BSC in a GERAN model, it has little to do with a radio communication equipment and is more a core network type node as it is a kind of access server combined with a protocol relay and a traffic forwarder.
Moreover, no manufacturer offers a combined MSC/SGSN product.